(1) Field of the Invention
The present invention relates to a wafer transfer equipment that is used when, for example, semiconductor wafers are transferred to a batch processing between wafer carriers and boats and a semiconductor device manufacturing apparatus using this wafer device transfer equipment.
(2) Description of the Related Art
A conventional technology will be described below referring to FIG. 12 and FIG. 13. A semiconductor wafer transfer equipment is provided with a first wafer elevator 3 that moves up and down from an internal specific position in a main body 2 of the equipment 1 to an external position at a specific height and a second wafer elevator 4 that moves up and down separately from the first wafer elevator 3. Between first and second wafer elevators 3 and 4, a wafer grip and transfer unit 5 is provided. A comb-teeth portion 7 is provided on the top of an elevating shaft 6 that is driven by an elevator drive unit (not shown) of first and second semiconductor wafer elevators 3 and 4, respectively. This comb-teeth portion 7 is provided with almost two symmetrically arranged comb-teeth members 8 and 9 with a comb-teeth opening formed to expand upward and the row of comb-teeth members set in the horizontal direction.
Wafer grip and transfer unit 5 is provided with a T-shaped supporting stay 10 at the upper side of main body 2 and a wafer gripper 12 that moves back and forth between the points directly above first wafer elevator 3 and the second wafer elevator 4 along a horizontal arm member 11 on the top of the supporting stay 10. Wafer gripper 12 has a gripping unit 14 comprising a pair of grippers 13a and 13b at the lower portion to grip a wafer and a drive unit 15 for the gripping operation of unit 14 and the reciprocation along horizontal arm member 11 at the upper portion.
The wafer transfer operations of the wafer transfer equipment are as described below. First, comb-teeth portions 7 of first and second wafer elevators 3,4 are positioned in main body 2 of the equipment and carriers 18 with semiconductor wafers 16 inserted in plural grooves 17 in the erected state are placed on the top surface of main body 2 so as to position immediately above comb-teeth portion 7 of first wafer elevator 3. Similarly, an empty boat 19 is placed on the top surface of main body 2 of the equipment to take in transferred semiconductor wafers 16 so as to position directly above comb-teeth portion 7 of second wafer elevator 4.
Then, elevating shaft 6 of first elevator 3 is moved up and semiconductor wafers 16 taken in carrier 18 are held one by one in the comb-teeth portions of comb-teeth members 8, 9 opposing to comb-teeth portions 7. Wafer gripper 12 of wafer grip and transfer unit 5 is positioned immediately above carrier 18, wafer grippers 13a and 13b are opened to readily grip wafers, and comb-teeth portion 7 is moved up to the wafer grip position with wafer gripper 12 by elevating shaft 6 of first wafer elevator 3. In succession, semiconductor wafers 16 are gripped by wafer grippers 13a and 13b, and comb-teeth portion 7 of first wafer elevator 3 is moved down.
Thereafter, wafer gripper 12 holding a semiconductor wafer 16 is moved horizontally to a position immediately above boat 19. Comb-teeth portion 7 is moved up by elevating shaft 6 of second wafer elevator 4 and is made to readily hold semiconductor wafer 16 in the comb-teeth openings 34 of comb-teeth members 8 and 9 one by one. Gripping of semiconductor wafer 16 by wafer holder 12 is cancelled and held by comb-teeth portion 7 of second wafer elevator 4.
Then, comb-teeth portion 7 of second wafer elevator 4 is moved down into the inside of main body 2. Semiconductor wafers 16 are transferred into boat 19 and the transfer of semiconductor wafers 16 into boat 19 from carriers 18 is finished. Semiconductor wafers 16 held in boat 19 are conveyed to, for example, a diffusion furnace/CVD system (not illustrated) and a specified processing is applied. Processed semiconductor wafers 16 are hung on semiconductor transfer equipment 1 and after the processing reverse to the above-mentioned process, transferred into carrier 18 and held therein.
In the conventional technology described above, it was necessary to pre-adjust the positions of grooves 17 holding semiconductor wafers 16 in the erected state to accurately agree with the comb-teeth opening positions of comb-teeth members 8 and 9 opposing to comb-teeth portion 7 of first wafer elevator 3. Thus, an accurate adjustment for the pre-positioning was required and labor hour and time were needed for the position adjustment.